1. Field of the Invention
The present invention relates to a can with a pull-ring opener, which is used as a container for beverages such as soft drinks, beer and the like.
2. Description of the Related Art
A can with a pull-ring opener has a spout that can be easily opened by lifting and pulling a pull-ring (or pull top, pull tab) pivotally supported by a rivet on a top wall of the can. Recently, such type of can has been widely used as containers for beverages such as soft drinks, beer and the like.
On the other hand, a spout of a can with a conventional pull-ring opener, once it is opened, is no longer reclosable, which causes inconvenience if the entire contents have not been consumed at once.
In view of the above, cans provided with sealing members that can reclose spouts once opened have been disclosed in some publications such as Unexamined Japanese Utility Model Publication No. 5-7632, Unexamined Japanese Patent Publication No. 8-244770 and U.S. Pat. No. 4,681,238.
The can described in Unexamined Japanese Utility Model Publication No. 5-7632 has an outer sealing plate disposed on an outer surface of a top wall of a can for sealing a spout once opened. Due to this structure, if the can is used for carbonated beverages such as beer or soda, which generate carbon dioxide inside the can that has been opened, a pressure in the can increased by carbon dioxide creates a gap between the top wall and the outer sealing plate, which may deteriorate the sealing function. Furthermore, as the outer sealing plate has substantially the same size as the top wall, a large amount of material is required for producing the can, and also the weight of the can itself is increased.
In the can described in Unexamined Japanese Patent Publication No. 8-244770, as a stopper for sealing an opened spout is made of materials such as gum, flexible plastic, vinyl and styrene foam, the can is expected to have high airtightness. However, due to the structure that the spout is sealed from an outside of a top wall, a pressure inside the can increased by carbon dioxide may push up the stopper and create a gap to allow the carbon dioxide to gradually leak through the gap. Moreover, the stopper made of materials such as gum, plastic or the like, which are different from metallic materials composing the can, makes the manufacturing process of the can complex and, when recycling the used can, the stopper made of alien materials would cause various problems including the necessity to classify the members depending on the materials.
In the re-closure device for containers disclosed in U.S. Pat. No. 4,681,238, after a pull-ring fixed to a top lid with a rivet is raised to expose a lid opening, the pull-ring is rotated about the rivet in that state so that a resealing member disposed on an inner side of the top lid rotates about the rivet to seal the lid opening. In this device, the resealing member having a similar shape to the opening tends to create a gap unless the opening and the resealing member are exactly overlaid. Thus, the opening cannot be sealed in a secure manner. Particularly, after opening a can with a pull-ring opener, as a sealing lobe is bent down into the interior of the can from an area around the rivet, rotation of the resealing member about the rivet is stopped by abutting against the bent sealing lobe, thereby failing to seal the opening completely.
On the other hand, a container made from a used can with a pull-ring opener provided with a function of closing a spout has been disclosed, for example, in Japanese Utility Model Registration No. 3052836.
In the closable container made from a used can described in Japanese Utility Model Registration No. 3052836, a rotating cover for reclosing the spout is attached after the can has been used. Therefore, as a container for liquids, the can hardly has sufficient tightness. In addition, as the rotating cover has a form of a relatively thin plate and is tightly attached to an outer surface of a top wall, it is difficult to manipulate the cover to open and close the spout.
An object of the present invention is to provide a can in which a spout after the can has been opened is securely sealed and also can be opened and closed with an easy operation.